Decurling device for a rolled recording paper

Abstract

A decurling device wherein paper is transported from a roll while being decurled by a decurling roller. A controller controls the decurling by temporarily stopping rotation of the decurling roller. Particular embodiments include provision of a pressing plate pressing the paper toward the decurling roller and control of the roller in accordance with curl of the paper by detection of diameter of the roll and by detection of path the paper follows during feeding.

What is claimed is: 
     
       1. A device for decurling a recording paper in a form of a roll, the device comprising: means for transporting the recording paper;   decurling means for decurling said recording paper while said recording paper is in transport, said decurling means comprising a decurling roller and decurling guide; and   control means for temporarily interrupting transport of said recording paper at said decurling means, said control means comprising a driver for driving the decurling roller and a controller which provides control signals to said driver;   wherein said controller controls said driver to temporarily stop a rotation of the decurling roller at a predetermined timing so as to control at least one of a duration and a frequency of interruption of the transport of the recording paper, and said controller controls the driver to temporarily stop said decurling roller rotation at said predetermined timing so as to permit a decurling of the recording paper at said decurling means;   the device further comprising curl sensing means for sensing a curl of the recording paper, wherein said control means controls the transport of the recording paper in response to an output of said curl sensing means.   
     
     
       2. A device for decurling a recording paper in a form of a roll, the device comprising: means for transporting the recording paper;   decurling means for decurling said recording paper while said recording paper is in transport;   driving means for driving said decurling means;   roll diameter sensing means for sensing a varying diameter of said roll; and   control means for controlling said driving means to interrupt the transport of the recording paper a number of times or a period of time in response to an output of said roll diameter sensing means.   
     
     
       3. A device for decurling a recording paper in a form of a roll, the device comprising: means for transporting the recording paper;   decurling means for decurling said recording paper while said recording paper is in transport, said decurling means comprising a decurling roller;   driving means for driving said decurling roller of said decurling means;   curl sensing means for sensing a size of a curl of said recording paper; and   control means for controlling said driving means to interrupt a rotation of said decurling roller at a predetermined timing in response to an output of said curl sensing means indicating that a size of the curl of the recording paper is greater than a predetermined size.   
     
     
       4. A device for decurling a recording paper in a form of a roll, the device comprising: transporting means for transporting the recording paper along a lower paper guide;   a decurling roller for bending said recording paper in a direction opposite to a curl direction of said recording paper;   a pressing plate rotatably mounted on a fulcrum so as to be rotatable about the fulcrum, an end of the pressing plate spaced from the fulcrum defining a bent portion which partially surrounds said decurling roller, said pressing plate being spring biased by a spring to rotate about the fulcrum in a direction toward the decurling roller so as to cause said bent portion to contact said decurling roller at a first portion of the decurling roller which defines an inlet side of the decurling roller with respect to an intended direction of paper transport, and at a second portion of the decurling roller which defines an outlet side of said decurling roller with respect to the intended direction of paper transport; and   a plurality of paper guide plates positioned after said transporting means and before said decurling roller with respect to the intended direction of paper transport, and positioned between said pressing plate and said lower paper guide so as to be spaced from each other to define a plurality of recording paper transport paths which lead to said decurling roller, wherein each of said transport paths guides recording paper with different curl sizes to said decurling roller;   a position of said fulcrum and positions of the first and second portions of the decurling roller where said bent portion of said pressing plate contacts said decurling roller being selected such that a force acting on said inlet side is greater than a force acting on said outlet side so as to create a tension on the recording paper between said inlet side and said outlet side.